The purpose of this competing continuation proposal is to extend a program of research that began in September, 1991 and has included (a) a controlled pilot phase efficacy study of the Preparing for the Drug Free Years (PDFY) intervention, (b) several consumer-oriented studies of factors influencing participation in family skills interventions, and (c) six waves of data collection in a prevention trial with three conditions--the PDFY, a second more intensive universal intervention called the Iowa Strengthening Families Program, and a control condition. [unreadable] The first aim of this proposal is to collect two more waves of prevention trial follow-up data, in order to examine sequences of intervention effects and long-term young adult outcomes of the interventions. The second aim is to examine the course and developmental etiology of substance use and abuse from young adolescence to young adulthood; the third aim is to examine the effects of adolescent substance use on mental health and behavioral outcomes among young adults. The three aims will be achieved through follow-up data collection across two important developmental phases of young adulthood, when participants are 21 and 24 years of age, along with analyses of these and earlier waves of data from the ongoing prevention trial. This trial began with the random assignment of 33 rural schools having a sixth grade and meeting criteria for the federal school lunch program. Multi-informant, multimethod measurement procedures at pretesting involved 667 families from the 33 schools. Retention rates have been comparable to those reported in reviews of longitudinal preventive intervention studies. Pilot phase and trial phase analyses to date, including multilevel analysis (mixed model ANCOVA, hierarchical linear modeling), and latent growth curve modeling, have shown (a) significant, positive effects of the interventions on effective parenting, young adolescent competencies, and adolescent substance use; (b) support for models of sequences of intervention effects; (c) support for models of family participation factors; and (d) evidence of hypothesized developmental etiological factors in youth substance use. Intervention-control differences on young adult outcomes will be examined via multilevel modeling and latent growth curve analyses. Planned modeling of intervention-related sequences of effects will include multisample structural equation modeling (MSEM) and latent growth curve modeling (LGCM) of interrelationships among targeted outcomes. MSEM and LGCM, along with Latent Transition Analyses, also will be used to examine developmental etiology and adolescent substance use effects on outcomes at the young adult developmental phases. [unreadable] [unreadable]